diff --git a/README.md b/README.md
index 2c18105..8b8d426 100644
--- a/README.md
+++ b/README.md
@@ -7,5 +7,5 @@ Go by Example book source.
 
 ```bash
 $ mate tool/index.txt
-$ go run tool/renumber.go
+$ tool/renumber
 ```
diff --git a/tool/renumber b/tool/renumber
new file mode 100755
index 0000000..ced5840
--- /dev/null
+++ b/tool/renumber
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+exec go run tool/renumber.go